Table 1.

Medication-related osteonecrosis of the jaws staging systems compared

Stage	AAOMS 2009 3	SICMF-SIPMO 2020 9
At risk category	No evidence of exposed or necrotic bone in patients who have been treated with bisphosphonates
Stage 0	Nonspecific clinical findings and symptoms such as jaw pain or osteosclerosis, but no clinical evidence of exposed bone
Stage 1	Exposed/necrotic bone in patients who are asymptomatic, with evidence of infection	Focal ONJ Clinical signs and symptoms: bone exposure, sudden dental mobility, non-healing post-extraction socket, mucosal fistula, swelling, abscess formation, trismus, gross mandibular deformity, and/or hypoesthesia/paresthesia of the lips CT findings: increased bone density limited to the alveolar bone region (trabecular thickening and/or focal osteosclerosis), with or without signs of: markedly thickened and sclerotic lamina dura, persisting alveolar socket, and/or cortical disruption 1A Asymptomatic 1B Symptomatic (pain and purulent discharge)
Stage 2	Exposed/necrotic bone associated with infection as evidence of pain and erythema of the region of exposed bone, with or without purulent discharge	Diffuse ONJ Clinical signs and symptoms: same as for Stage 1 CT findings: increased bone density extending to the basal bone (diffuse osteosclerosis), with or without signs of: prominence of the inferior nerve canal, periosteal reaction, sinusitis, formation of sequestra, and/or oroantral fistula 2A Asymptomatic 2B Symptomatic (pain and purulent discharge)
Stage 3	Exposed/necrotic bone in patients with pain, infection, and one or more of the following: pathological fracture, extraoral fistula, or osteolysis extending to the inferior border or sinus floor	Complicated ONJ Clinical signs and symptoms: same as for Stage 2, with one or more of the following: extraoral fistula, displaced mandibular stumps, nasal leakage of fluids CT findings: osteoscleorosis of adjacent bones (zygoma and hard palate), pathological mandibular fracture, and/or osteolysis extending to the sinus floor